Fair Value (Additional Information) (Details) - USD ($)	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans, allowance allocation recorded	$ 21,254,000		$ 12,307,000	$ 21,254,000	$ 12,307,000	$ 12,674,000	$ 17,063,000	$ 12,353,000	$ 11,566,000
Chargeoffs to impaired loans	79,000		$ 30,000	1,754,000	$ 94,000
Valuation allowance related to mortgage servicing rights	17,000	$ 0
Write downs recorded in other real estate owned	0			0		0
Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans, allowance allocation recorded	$ 91,000			91,000		$ 161,000
Chargeoffs to impaired loans		$ 298,000		$ 364,000
Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additional adjustment	0.05%			0.05%
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additional adjustment	0.75%			0.75%